Comprehensive Calculator Guide
The apnea–hypopnea index (AHI) calculator works out breathing pauses and shallow-breathing episodes per hour of sleep from your sleep study report, and grades the result: normal, mild, moderate or severe. 40 apneas and 60 hypopneas over 7 hours give an AHI of 14.3, mild sleep apnea. It also explains what the number means and common treatments.
Apneas, hypopneas and grades
An apnea is airflow stopping for at least 10 seconds; a hypopnea is a marked drop for at least 10 seconds with lower oxygen or a brief arousal. AHI adds both and divides by hours slept: under 5 normal, 5–14 mild, 15–29 moderate, 30+ severe for adults (AASM).
Untreated apnea brings daytime sleepiness and is linked to high blood pressure, heart disease and road accidents. CPAP is the standard treatment for moderate and severe cases; weight loss and side-sleeping often help mild ones.
How to Use
- Enter the apneas and hypopneas from your sleep study report.
- Enter the hours actually slept.
- Press “Calculate AHI” to see the index and its grade.
Formula Used
AHI = (apneas + hypopneas) ÷ hours of sleep
Practical Examples
- Example 1
- 40 + 60 events in 7 hours: 14.3, mild.
- Example 2
- 150 + 90 events in 6 hours: 40, severe.
Important Tips
- Use hours actually asleep, not time in bed.
Common Mistakes to Avoid
- Applying adult limits to children.
Frequently Asked Questions
- What is a normal AHI?
- Under 5 events an hour for adults.
- How is AHI calculated?
- Add apneas and hypopneas and divide by hours of sleep.
- When is CPAP needed?
- Usually for moderate or severe apnea (15+), sometimes for mild with clear symptoms.